Study On Preparation And Biomedical Application Of Vancomycin-immobilized Magnetic Nanoparticles

There is no doubt that instant and sensitive detection of pathogens such as bacteria,viruses offers obvious clinical benefit. However, there is, to date, no general assay that could detect bacteria at very low concentrations without incubation or amplification by polymerase chain reaction(PCR). The presence of the impurities in a complex sample may suppress or interfere the signal of the target microorganism. Separation of target pathogen from the samples can lead to pre-enriching and decreasing the interference from the matrix samples. The ideal distribution of drugs is that they can distribute selectively in the pathological site and keep at a level at some time. Magnetic nanoparticles show superparamagnetism as well as special properties of other nanoparticles. Different biofunctional molecules can be anchored onto magnetic nanoparticles by surface modification. These offer their potential applications in the field of bacteria separation, drug targeting and so on.Magnetite nanoparticles about 10nm were prepared by chemical coprecipitation. The superparamagnetism were confirmed by PPMS measurement. After washing with dilute acid solution, the dispersity and stability of the as prepared nanoparticles in water solution were improved.Magnetite nanoparticles coated with (γ-aminopropytytriethoxysilane were prepared by silanization reaction. Norvancomycin Hydrochloride(Van) modified magnetite nanoparticles were prepared by the reaction between the amino group on the nanoparticles surfaces and the carboxylic group of Van molecules.By a separation assay of S. aureus and E. coli BL21, it was proved that Van modified magnetite nanoparticles could selectively capture S. aureus and then could be isolated readily by applying an external magnetic field. The biofunctional magnetic nanoparticles of Van modified magnetite nanoparticles can inhibit the growth of S. aureus at a targeted area.